The formation of 23.0 g of O2 results in

Question

Consider the reaction.

2Fe2O3⟶4Fe+3O 2ΔH∘rxn=+824.2 kJ

The formation of  of O2 results in

Answer 1

2Fe₂O₃ ==> 4Fe + 3O₂ ΔH∘rxn = +824.2 kJ

23.0 g O₂ x 1 mol O₂/32 g = 0.719 moles O₂

According to the balanced equation, formation of THREE moles O₂ requires 824.2 kJ of energy. Thus...

0.719 moles O₂ x 824.2 kJ/3 moles O₂ = 198 kJ

The formation of 23.0 g of O₂ results in 198 kJ of energy being used.

(The reason it is being used, and not being given off is because ∆H is positive = endothermic)